//---------------------------------------------------------------------------
// PatchGenerator.h
//---------------------------------------------------------------------------
//                           -=* VPatch *=-
//---------------------------------------------------------------------------
// Copyright (C) 2001-2005 Koen van de Sande / Van de Sande Productions
//---------------------------------------------------------------------------
// Website: http://www.tibed.net/vpatch
//
// This software is provided 'as-is', without any express or implied
// warranty.  In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
//    misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.

#if !defined(PatchGenerator_H)
#define PatchGenerator_H

#include <iostream>
#include <vector>
#include "GlobalTypes.h"
#include "ChunkedFile.h"

using namespace std;

typedef struct SameBlock
{
	TFileOffset sourceOffset;
	TFileOffset targetOffset;
	TFileOffset size;
} SameBlock;

class PatchGenerator
{
protected:
	bifstream& source;
	TFileOffset sourceSize;
	bifstream& target;
	TFileOffset targetSize;
	//bostream& patch;

	// cache
	unsigned char* targetCData;
	TFileOffset targetCDataBaseOffset;
	TFileOffset targetCDataSize;

	SameBlock* findBlock(ChunkedFile* sourceTree,
		TFileOffset targetFileStartOffset);
	//    SameBlock* findBlock(ChunkedFile* sourceTree, unsigned char* targetData, TFileOffset targetStartOffset);
	void improveSameBlockMatch(SameBlock& match, TFileOffset currentBest = 0);
public:
	TFileOffset blockSize;
	int32 maxMatches;
	//bool beVerbose;

	// load in the source, target streams
	PatchGenerator(bifstream& source, TFileOffset sourceSize, bifstream& target, TFileOffset targetSize);
	~PatchGenerator();

	// construct the actual patch
	void execute(vector<SameBlock*>& sameBlocks);
};

#endif // PatchGenerator_H
